Many polymers derived from various marine sources and microorganisms possess some important biological properties such as biocompatibility, biodegradability, and bioadhesivity that make them attractive as pharmaceutical excipients in various pharmaceutical dosage forms. Moreover, these polymers can be modified physically and/or chemically to improve their biomaterial properties.In this volume, Natural Polymers for Pharmaceutical Applications, Volume 2: Marine- and Microbiologically Derived Polymers, looks at how these polymers have been explored and exploited for pharmaceutical uses, such as in tablets, microparticles, nanoparticles, ophthalmic preparations, gels, emulsions, suspensions, etc. Some commonly used marine- and microbiologically derived polymers used as pharmaceutical excipients include alginates, agar-agar, gellan gum, carrageenan; chitosan, xanthan gum, and others. The book focuses on important recent advances from experts around the world on marine-derived polysaccharides and pharmaceutical applications of alginates, agar-agar, gellan gum, carrageenan, chitosan derivatives, xanthan gum.